1. Field of the Invention
The present invention relates to an exhaust gas treatment system which treats a gas containing hydrogen and a silane gas discharged from a semiconductor fabrication equipment.
2. Description of the Related Art
An exhaust gas which is discharged from a semiconductor fabrication equipment, and particularly, a plasma CVD device that forms a film of thin-film silicon used in a solar cell contains monosilane that needs to be detoxified, hydrogen that does not need to be detoxified, and fine particles (high-order silane) in a mixed state. In an existing exhaust gas treatment device, fine particles are removed by a filter, nitrogen is added to a mixed gas (hydrogen/monosilane=2 to 100) containing remaining monosilane and hydrogen, and the resultant gas is treated by a detoxifying device. The addition amount of nitrogen is adjusted so that the concentration of monosilane becomes 2% or less from the viewpoint of the production of powder.